Means for ascertaining the power factor in alternating-current systems.



No. 806,573. 1 PATENTED DEC. 5, 1905 J. L, ROUTIN. v MEANS IOR 'ASCERTAINING' THE POWER-TAGTOR IN ALTERNATING CURRENT SYSTEMS.

APPLICATION FILED NOV. 21, 1904.

JOSEPH Louis ROUTIN, or Lroti tjnnnon.

MEANS FOR ASICERTAINING THE POW-ER FACTOR m ALTERNATIV Application filed November 21,1904. 8eria1No.2S3,682.

-.To all whom it may concern: Be it known that I, JOSEPH LOUIS ROUTIN,

engineer, a citizen of the French Republic,

.residingat Lyon, France, have inventedcer- .tain new and useful Improvements in Means for Ascertaining the Power Factor in Alternating-Current Systems, of which the followingis a;specificati on.

This-invention relates to new or improved means for ascertaining in alternating-current systems the factor by which the apparent power. must be multiplied in order to obtain the actual power in watts.

[n the accompanying drawings, Figures 1 and 2 are diagramsillustrating the invention. The apparatus comprises a transformer T, Fig. 1, comprising three coils 61, 722, and 6s.

The coil 61 carries the main current, the coil 52, consisting of a small number of turns of thick wire, is connected to a rheostat R of adjustable resistance and free from self-induction, and the coil bs'is connected to one of the mains L1 and to one terminal of a voltmeter V, the other terminal of which isconnected to the other main L2, but these connections to the mains are interchangeable at Willby means of a switch 0.

Two keys f1 and ft allow of using the volt H meter V for measuring the potential D between the mains L1 and L2 or the potential D between the terminals of the coil 63.

The method for making a measurement is as follows: The key fl is moved into the position indicated in the drawings by dotted lines, and the potential between the mains, which shall be called 61, is read ofl the voltmeter. The key 1% is thereupon moved back to its original position and the key f2 is moved into the position indicated in the drawings by dotted lines. The rheostat R is thereupon adjusted until the potential between the terminals of the coil 63, which shall be called 1, is equal to 61. under these conditions the potential on the coil 63 is substantially in phase with the current on the mains and that the said potential is also at all times proportional to the said current. The key f2 is then moved back to its original position, and the potentialml resulting from the opposition of 1 to @1 is noted. Then as will be demonstrated hereinafter. Since @1 1s 1n practlce a constant, a special scale can be cos. 5 =1 Specification of Letters Iatent, V;

The transformer T is so constructed that URRENT SYSTEMS.

Patented Dec. 5, 1905.

traced on the voltmeter to directly indicate ,0 or the power factor (1 5%, To obtam a larger approximatiom the potential m2 resulting from the addition of 1 to 61 can be ascertained. To do this, the switch C is operated. The angle P will then be given by'the equation tan. g as will be seen from Fig. 2. I will now demonstrate the first equation cited. Let e be the instantaneous potential on the terminals, 61 the effective potential on the terminals, 11 the instantaneous tension, 61 the effective tension, T the inverse frequency, W thepower in watts, 8 the auxiliary electromotive force supplied by the transformer, 1 the effective value of m1 the efi'ective value of the resultant of e and The valueto be ascertained is e a a 1:,

now

The reading on the voltmeter gives If the resistance in the secondary circuit is so regulated that 0 then cos 1 2 The voltmeter V must have sufiicient resistance to render the consumption of power therein immaterial to the measurements, for this purpose a direct-current voltmeter preferably used in series with a small electrolytic cell E. If the coil 62 were dispensed with and the rheostat R connected to the terminals of the coil 53, the rheostat must have a very much higher resistance and must comprise a long thin wire instead of massive bars. This would render it difiicult, to obtain a continuous variation of its resistance by means of a sliding contact. It is solely for this reason that the auxiliary coil In is used for regulating the resultant flux. If it is desired to obtain lowtension readings with the same approximation as for the full load, the coil In is preferably divided into sections, as indicated in Fig. 1, adapted to be placed in series or in parallel with each other in order to allow of using approximately the same number of ampereturns.

To avoid the necessity of using a too-large number of turns in the coil 63, lower tension than 61 can be used for exciting the coil Z13. For this purpose an ordinary transformer can be used or a resistance 0', Fig. 1, free from self-induction placed between the mains L1 L2, one terminal of the coil 61 being connected to a suitable point on this resistance and the other terminal being connected to the main. These arrangements allow of regulating at will the fraction of 61 to be used and of keeping this fraction of a constant value in order that the special scale on the voltmeter can be used for ascertaining the power factor.

I declare that what I claim is-r 1. In alternating-current systems, means for ascertaining the voltage factor of power, comprising in combination with two mains a transformer excited by said mains, means for controlling the potential on the terminals of the secondary transformer-coil independently from the mains, means for measuring said potential, means for measuring the potential on said mains, and for measuring the resultant of said potential difi'erences.

2. In alternating-current systems means for ascertaining the voltage factor of power, comprising in combination with two mains a transformer excited by said mains, means for controlling the potential on the terminals of the secondary transformer-coil independently from the mains, means for measuring said potential, for measuring the potential on said mains and for measuring the resultant of said potential differences in parallel and in series.

3. In alternating-current systems, means for ascertaining the voltage factor of power, comprising in combination with two mains a transformer excited by said mains, means for reducing the amperage in the primary coil of said transformer, means for controlling the potential on the terminals of the secondary transformer coil independently from the mains, means for measuring said potential, for measuring the potential on said mains and for measuring the resultant of said potential differences.

In witness whereof I have signed this specification in the presence of two witnesses.

JOSEPH LOUIS ROUTIN.

Witnesses:

MARIN VACHORY, AIME FLnoHE'r. 

